Move parseNetTestOptions to oonicli
Add NetTestCase option validation

Options that are passed to the NetTest constructor must be valid
options defined in the NetTestCase UsageOptions with optParameters.

Also handle the case where inputFile is *not* a required option and not
supplied gracefully.
Add tests for missing required options and invalid options
Move setUpNetTestCases into start() and set up measurementManager

Also updates the test cases.
Merge remote-tracking branch 'aagbsn/rebase_test_nettest' into tmp

* aagbsn/rebase_test_nettest:
  Move setUpNetTestCases into start() and set up measurementManager
  Add tests for missing required options and invalid options
  Add NetTestCase option validation
  Move parseNetTestOptions to oonicli